1. Field of the Invention
The present invention relates to a bathtub and a bath system, either having a pump, which comprise a pump unit and a motor unit separated from the pump unit.
2. Description of the Related Art
A pump unit is known which is designed for use in combination with a bathtub, for pumping hot water from the bathtub and jetting the hot water into the bath through a nozzle. The pump unit comprises a pump and a motor which are coupled to each other, and located within the bathtub. The shaft of the pump is mechanically connected to the shaft of the motor by means of a coupling. There remains the risk that hot water leaks from the chamber of the pump into the motor along the shafts of the pump and motor.
Of course, a watertight sealing member, such as an O-ring, is interposed between the motor shaft and housing of the motor, thereby to prevent the hot water from leaking out of the pump chamber. Despite this, the sealing member can not achieve sufficient sealing since it is in sliding contact with the shaft of the pump. In fact, it cannot prevent the hot water, which wets the shaft of the pump, from leaking from the pump housing into the motor through the gap between the motor shaft and the sealing member. The not water flowing into the motor reduces the operating efficiency of the motor, however small the amount of the hot water. Inevitably, the reliability of the pump unit is not sufficiently high.